Method of



(No ModeL) O. P. GROUT.

METHOD OF APPLYING METALLIC TOOTH GROWNS.

. Patented June 2, 1885.

N. FUERS, Phulo-Lflhogripher, wzmin tmnc.

NITED STATES PATET OHARLESP. GROUT, OF NEW YORK, N. Y.

SPECIFICATION forming part of Letters Patent No. 319,238, dated June 2, 1885.

Application filed April '1, 1885. (No model.)

To all whom it may concern..-

Be it known that I, CHARLES P. GROUT, of the city and county of New York, in the State of New York, have invented a new and useful Improvement in the Method of Making and Applying Metallic Tooth'Orowns and Appliances therefor, of which the following is a specification. According to the ordinary method of makmg and applying metallic toothcrowns the tooth root or stump is first trimmed or cut to the proper shape, a band portion, of gold or other thin metal, of proper size, is then made, and, after placing it upon the root or stump, is forced down below the free margin of the gum, and to or near to the alveolar border. The metal of which the band is composed is comparatively hard, and so unyielding that the band has usually to be driven down on the root or stump with a mallet to bring it to its proper place. Not only has the band to be forced down on the root or stump in order to bring it to its proper form, but frequent visits of the patient are necessary in order that the band and crown may be placed and forced down into position on the root or stump from time to time during the process of making it.

The objects of my invention are to relieve the patient in a great measure from the annoyance and pain incident to the ordinary practice observed in making and applying artificial tooth-crowns, and also to enable the crowns to be fitted more accurately and carefully, so that when finally placed upon the roots or stumps a firmer and better piece of work in every respect will be produced.

In carrying out my invention the root or stump may be shaped or trimmed in the usual way, or according to the method and by means of the appliances set forth in my application for Letters Patent filed February at, 1885, the serial number of which is 154,937. In lieu of first applying a band of gold or other metal, which is to form the crown to the root or stump, I employ soft-metal tubes, of block-tin or other metal sufficiently yielding and flexible to enable them to readily adapt themselves to the shape of the root or stump. I first take a plaster impression of the mouth, and from this impression I can ascertain what sizes of soft-metal tubes are required. I then cut the lower ends of the tubes to conform to the profile of the gum, which is given by the plaster impression. I then force each soft-metal tube down on the root or stump to the desired position below the free margin of the gum, and to or near to the alveolar border. The tube which I employ is sufficiently flexible to enableit to be forced down to the desired position on the root or stump by means of the thumb and fingers applied thereto, and will not require any hammering with a mallet to bring itto its place. After it is in position it is cut off to the desired length, so that its up per end will be a little above or below the end of the exposed root or stump, as may be desired. I then form in the end of the root or stump, by enlarging the nerve-canal, a holeor socket to receive the pin by which the finished crown is to be held in place. All the roots or stumps which are to be crowned being thus provided with soft'metal tubes and pins, a plaster impression of the mouth is taken, and in removing this plaster impression the tubes and pins will remain embedded therein, and will all, or most all, of them come off with the impression. Where the pins in any roots are slanting, they may be drawn out first through the top of the impression-cup. In the case of molar teeth or other teeth which are inclined or slant-ed it may be necessary to take an impression of them and the adjacent portion of the mouth separately, inasmuch as their impression and tubes would not readily draw of with the general impression of the other teeth and tubes. In the case of molar teeth where the natural crown or a portion thereof still remains, I take a strip of sheet metal of proper width to extend from a point at or near the alveolar border up to the bulge of the tooth, and, placing it around the tooth, I wrap it with waxed silk or wire and force it down to or near to the alveolar border. I then take an impression of the tooth from the bulge upward in plaster, the end of the sheetmetal band forming a shoulder in the plaster, and after the plaster is removed the band is taken off and set into its proper position in the plaster impression. Having thus obtained by means of the plaster impression the impressions of the soft-metal tubes and form of the roots and stumps above and below the free margin of the gum, I place them in suitable investments and obtain from them in fusible metal a perfect fac simile of the roots or stumps, both above and below the gum, and also a facsimile of the mouth. I use fusible metalsueh as may be composed of lead, tin, and bismuth, because it will have very little shrinkage in cooling, and will not when molten melt the soft-metal tubes. Such metal will melt at about 200 Fahrenheit. I may first make a facsimile of the molar tooth from the plaster impression and metal band taken therefrom and place this metal facsimile in the main impression-of the other teeth, so that it will be incorporated with the fae-simile obtained from said main impression in the 'op-' eration of casting. The facsimile of the roots or stumps having been thus obtained, I fit upon them, instead of upon the natural teeth. all'the crown-bands of gold or other permanent metal, and during the whole operation of form-' ing the crowns they may be fitted upon the metal cast as often as may be desired, and a more secure and more accurate fit of the band and crown can be obtained than was. possible by the old method of applying the band or crown frequently to the root or stump itself. By this method I not only produce crowns which will fitthe roots or stumps to which they are applied mueh closer, and are therefore less liable to work loose, but I also save the patient a vast amount of pain and annoyanceincident to the ordinary method of making and applying tooth-crowns.

In the accompanying drawings, Figure 1 represents an elevation of a tooth root or stump having asoft-met'al band applied to it,the band being shown in section, and includes a sectional view of the alveolar process and gumtissue. Fig. 2 represents an elevation of a molar tooth wit-h a soft-metal band extending upward from below the gum to the bulge of the tooth, also a sectional view of the alveolar process and gum-tissue. Fig. 3 represents a perspective view of the plaster impression in which the soft-metal tubes and the pins are embedded. Fig. 4 representsa sectional view of a plaster impression taken from a molar tooth, and in which the form of the toothfrom the bulge upward is in the plaster, and its form from the bulgeinwardis given by a piece of soft metal which is bent into annular form and set in the plaster. Fig. 5 is a perspective view of a metal fac-simile which has been produced from the plaster impression and tubes. Fig. 6 is a sectional view through such facsimile, the section being taken through one of the projections which represent the tooth-' roots; and Fig. 7 is a perspective view of the metal facsimile of a molar tooth. All figures except Figs. 3 and 4 are on an enlarged scale.

Similar letters of reference designate corre-- sponding parts in the several figures.

A designates the root or stump; B, the alveolar process; 0, the gum-tissue. The exposed portion of the root or stump is first trimmed or shaped to the desired form from the alveolar border a outward. A hole or socket, 0, is then formed by enlarging the nerve-canal or nearly to the alveolar border.

otherwise, and in this hole is placed a pin, 1), the purpose of which will be hereinafter explained.

D designates a soft-metal tube, which may I be of block-tin or composition, and which should be sufficiently yielding and flexible to enable it to be forced down below the margin of the gum and clear to or near to the alveolar border. This may be done without any hammering or pounding with a mallet. The outer bands D and pins 1), I take in the ordinary way a plaster impression of the mouth, and when it is removed all,or nearly all, of the soft-metal tubes and pins will come off with and remain embedded in the impression E, as shown in Fig. 3, and will project from the plaster a distance equal to the length of the root or stump below the gum and down to or Any tubes or pins which do not draw off with the plaster impression may be removed separately and placed in their proper seats in the impression. Where there are any molar or other teeth which, by reason of their being inclined, will not permit of the bands being drawn off with the others, all of which have the same general direction, a plaster impression of such inclined teeth is to be taken separately. of molar teeth where the crown is well preserved outward beyond the bulge of the tooth, it will be necessary to apply a strip of metal, D*, bent into annular form and forced down under the free margin of the gum, and then wrapped around with waxed silk or wire as shown in Fig. 2. This band should be of In the case IIO a width sufficient to extend from below the gum outward to the bulge of the tooth, and when the plaster impression is taken it will have the form of the tooth from the bulge outward, and a shoulder or seat formed by a band, D= band D will be removed and set into its place in the impression. In Fig. 4 I have represented such impression 111* with the band portion D placed therein. I afterward place the impression E E in suitable investments, and by means of fusible metal which will melt at a low temperature I obtain from them facsimiles of themouth and roots or stumps, as shown in Figs. 5, 6, and 7. Figs. 5 and 6 represent such a facsimile or cast, F, as would be obtained from the impression shown in Fig. 3, and has projecting from it pegs or projections A*, which conform to the shape of the tooth roots or stumps, and which have at their bases grooves or channels (1, representing the space inside of the free margin of the gum. The projection A* from its outer'end down to After the impression is removed the the bottom of groove d is a true facsimile of the root or stump'from its outer end inward to the alveolar border, and under the free margin of the gum.

Fig. 7 represents such a cast or facsimile, F*, as would be obtained from the plaster impression shown in Fig. 4, and the peg or projection A* is a true facsimile of a molar tooth from its outer end inward to, or nearly to, the alveolar border, and under the free margin of the gum. I may first make a metal facsimile, as is shown in Fig. 7, from an impression of a molar tooth, and then place that facsimile in the impression shown in Fig. 3 before making a metal facsimile therefrom. The metal facsimile shown in Fig. 5 will then have incorporated in it the facsimile of the molar tooth.

, To the projections A on the metal facsimile the bands which are to be applied to the tooth roots or stumps are carefully fitted, and it will be readily understood that in this way the bands and crowns may be fitted far more accurately than they can be when that work has to be done in the mouth of the patient, and all the pain and annoyance to the patient caused by driving the bands down on the roots or stumps and frequently trying them on in the course of manufacturing is avoided. After the band has been carefully fitted to the metallic projection and the crown completed, it

will be found that the crown will fit snugly and firmly upon the natural root or stump.

Where a number of crowns are to be connected by a bridge, all the work may be performed upon a metal facsimile, and it will be found that when the bridge and the crowns incorporated therein are placed in the mouth of the patienta good fit and a serviceable piece of work will be produced.

In the projections A upon the metal facsimile F are formed holes 6, and after the metal crowns are fitted to these projections the pins which are to secure the crowns in place on the teeth may be fastened in the crowns, and will be given the desired slant by fitting in the holes 6. 1

What I claim as my invention, and desire to secure by Letters Patent, is

1. The method of obtaining a metallic facsimile of tooth roots or stumps on which to fit metallic tooth-crowns, consisting in trimming or shaping the natural tooth roots or stumps to the desired form; in then enveloping such roots or stumps in soft metal, which is forced down below the free margin of the gum; in then taking a plaster impression of the natural roots or stumps with the soft metal in place, and removing the plaster impression and soft metal from the mouth, and in finally casting from this impression and soft metal a metallic facsimile having projections which correspond to the form of the natural roots or stumps, substantially as and for the purpose herein described.

2. The method of obtaining a metal facsimile of natural tooth roots or stumps on which to fit metallic tooth-crowns, consisting in trimming or shaping the natural roots or stumps to the desired form, and forming in them pin holes or sockets; in then applying soft-metal tubes to the roots or stumps and pressing them down below the free margin of the gum; in inserting pins in the holes or sockets; in then taking a plaster impression of the natural roots or stumps and the softmetal tubes and pins; in then removing the plaster impression, with the soft-metal tubes and pins, from the mouth, and in finally casting from this impression, with its tubes and pins, a metal facsimile having projections in which are holes or sockets, and which correspond in form to the natural roots or stumps, substantially as and for the purpose herein described.

3. A metallic facsimile on which to fit metallic tooth-crowns,having upon it projections provided with grooves at their bases, and corresponding in form to the natural tooth roots or stumps, substantially as and for the purpose herein described.

GHAS. P. GROUT.

Witnesses:

O. HALL, FREDK. HAYNES. 

